In a time-of-flight (TOF) depth camera, light pulses are projected from a light source to an object in an image environment that is focused onto an image sensor. It can be difficult to fill the image environment with illumination light, as the image environment may have a sizeable volume and may have a cross-sectional shape (e.g. rectangular) that can be difficult to achieve with a desired intensity profile. Further, the imaging optics may have a large depth of field in which a consistent projected light intensity is desired.
Some previous approaches to filling image environments with light use high-order optics to shape diverging light emitted from side-emitting light sources. However, such approaches typically require precise design and manufacturing control of the angular distribution of the light in order to fill the image environment.